Buoyant metal/air battery

Abstract

The invention disclosed is a floating metal/air battery wherein the anode is immersed in an electrolyte, and the cathode is exposed to the atmosphere. An electro-conductive path between the anode and cathode is achieved by a wick means in contact with the electrolyte. Embodiments are described for use in sea-water and in fresh water.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A floating metal/air battery, comprising (a) a metal anode,   (b) an air cathode,   (c) means for completing an electro-conductive path from the anode to the cathode, and   (d) floatation means, such that in use the metal anode is immersed in a suitable electrolyte and wherein the completing means is in contact with the electrolyte.   
     
     
       2. A battery according to claim 1, wherein the electrolyte is selected from solutions in water of suitable salts, bases and acids. 
     
     
       3. A battery according to claim 2, wherein the metal anode is selected from magnesium, aluminum, zinc and suitable alloys thereof. 
     
     
       4. A battery according to claim 3, wherein the cathode is constructed to facilitate run-off of liquid upon which the battery is floating. 
     
     
       5. A battery according to claim 4, wherein the anode and cathode are arranged substantially parallel to each other. 
     
     
       6. A battery according to claim 5, wherein the floatation means separates the anode and cathode. 
     
     
       7. A battery according to claim 6, wherein said completing means is a wick attached to the cathode, made of a suitable electrolyte absorbent material which is stable in the electrolyte. 
     
     
       8. A battery according to claim 7, wherein the material is a glass-vinyon paper. 
     
     
       9. A battery according to claim 8, wherein the floatation means includes an opening therethrough, and wherein the wick is positioned in said opening. 
     
     
       10. A battery according to claim 9, wherein the electrolyte is sea water upon which the battery is floating. 
     
     
       11. A battery according to claim 9, wherein the floatation means comprises a pair of floating members, said opening being between said members. 
     
     
       12. A battery according to claim 10, wherein the floatation means comprises a rectangular frame member, said opening being located centrally thereof and being closed at one end by the anode to define a compartment open at the other end, and wherein a second opening is provided in said compartment to permit entry of the electrolyte to contact said wick. 
     
     
       13. A battery according to claim 12, wherein said second opening is provided in said float below the water line. 
     
     
       14. A battery according to claim 12, wherein said second opening is provided in the anode. 
     
     
       15. A battery according to claim 7, wherein the anode and cathode are arranged substantially perpendicular to each other. 
     
     
       16. A battery according to claim 9, wherein the floatation means comprises a rectangular frame member, said opening being located centrally thereof, and further comprising a reservoir for said electrolyte attached to said frame such that the anode and wick extend into the reservoir. 
     
     
       17. A battery according to claim 16, further comprising a plurality of separate spaced cells electrically connected in series. 
     
     
       18. A battery according to claim 17, including a port in each cell to provide an electrolyte path between the cells, said ports being located to maximize the distance between the ports in adjacent cells. 
     
     
       19. A battery according to claim 9, 16 or 17, wherein the air cathode comprises about 3.6 mg/cm 2  manganese dioxide, 20 mg/cm 2  activated carbon and 5.2 mg/cm 2  polytetrafluoroethylene, spread evenly on both sides of a nickel screen.